The Morphology of Ruppia Maritima. 104 
5. The floral scale leaf (fs/), adherent to the base of the peduncle 
in a position corresponding to that of the vegetative scale leaf ; 
6. The branch (avr), arising in the axil of the upper subfloral 
leaf ; 
7. The upper subfloral leaf (wp. sf/).! 
4, Summary of Distinguishing Characters. 
Irmisch (1851) has described the inflorescence in Ruppia rostel- 
fata. His account is in part as follows: “Die folia floralia bilden 
nun zwei Achseln, aus denen Zweige hervorbrechen, welche sich 
folgendermassen verhalten. Das erste tief an der Basis der Zweige 
stehende Blattgebilde ist eine diinnhdutige abgestutzte lanzettliche 
Schuppe, die sich um den Grund des Zweiges herumlegt. Ich will 
sie Vorblatt nennen. Es steht dasselbe, wie das auch sonst regel- 
massig der Fall ist, mit seiner Riickseite wegwarts vom Mutterblatte 
des Zweiges und dem Bliitenstande A zugewendet”;—and further, 
“Der Zweig in der Achsel des obern fol. flor. ist dem des untern 
in der aussern Bildung gleich.” 
In this and his description following, it is clearly evident that 
Irmisch considered the floral scale leaf and the vegetative scale 
leaf in an inflorescence to be identical, for he alludes to nothing but 
a vegetative scale leaf (Vorblatt) at the base of each branch. Of 
course it is possible that no floral scale leaf, as such, occurs in 
Ruppia rostellata, yet the two species are evidently quite similar. 
For example, Sauvageau (1891. I) finds no differences in the struc- 
ture of their foliage leaves. 
To sum up the differences between floral and vegetative scale 
leaves, they are in brief as follows. 
1. Shape. The floral scale leaf differs markedly in shape from 
the vegetative scale leaf. A large number of specimens was examined 
and this difference was constant. 
2. Position. As shown in Text-fig. 20, but more clearly were the 
section cut at a lower plane, the floral scale leaf does not envelop 
the axillary shoot as does the vegetative, but is turned toward and 
partially surrounds the young flower or the peduncle, according to 
the stage of floral development. 
3. Development. The growth of the floral scale leaf is always 
correlated with the growth of the peduncle and flower—even when 
the axillary structure adjacent is as yet rudimentary. In case the 

1 The axillary scales have been purposely omitted. The cross section 
5 pur} y 
represented in Text-fig. 20 was cut above them. 
